The overall objective of this project is to study stress-alcohol interactions in male and female rats. Several unique and important questions will be addressed: How does a stressful situation affect the biochemical homeostasis (plasma catecholamines) of the rat? What is the genetic component of this stress response? How does alcohol reduce and antagonize the stress response? Are rats which show a large stress response more affected by alcohol than are rats which show a low stress response? Do high or low stress responders differ in their voluntary alcohol intake during rest and stress? What other biochemical changes (brain biogenic amines, other plasma biochemicals) accompany the plasma catecholamine stress response? What are the correlations between biochemical and behavioral stress responses? Do male and female animals respond differently to stress and/or alcohol? The proposed experiments are a continuation of ongoing studies in the laboratory of the principal investigator designed to answer the above questions. They involve: 1) breeding of rats for their plasma catecholamine stress response by mating "high" and "low" stress responders selectively; 2) measurements of a number of plasma and brain biochemicals in these selectively bred animals over generations; 3) study of behavioral correlates in these selectively bred rats and 4) determination of voluntary alcohol consumption in these selectively bred "high" and "low" stress responders during rest and stress. Indirect evidence is available that stress and a genetic vulnerability play a role in the excessive alcohol consumption of some individuals. However, direct evidence on the role of stress and genetics in the etiology of alcoholism are often difficult to obtain in man. This study will supply scientific data on the stress- alcohol interaction and its genetic component. Our data can then be used to interpret more meaningful human studies, to identify individuals at high risk for alcoholism and to prevent or treat alcoholism by antagonizing specific stress responses with measures other than alcohol.